Nigeria's state security force says its agents exchanged gunfire with militant group Boko Haram in the capital, Abuja, early Friday.
A reporter for VOA's Hausa Service says seven young men were killed and about 10 others injured in the clash, which occurred shortly after midnight.
The state security force says its agents, acting on a tip-off, had gone searching for weapons said to be buried behind a community for Nigerian parliament members.
It says the team came under heavy gunfire and responded. It says 12 people were later arrested.
Locals told VOA they doubted the young men were Boko Haram members. No weapons were found at the site.
The violence followed a major attack in Nigeria's Borno state blamed on the Islamist militant group.
Nigerian officials say the militants killed at least 87 people in and around the town of Benisheik, and that scores of homes and buildings were burned.
Local witnesses told VOA that the Boko Haram fighters were better armed than soldiers who tried to fight them, and that the militants looted the town, taking away food and numerous vehicles.
The group says it is fighting to impose a strict form of Islamic law on Nigeria's Muslim-majority north. The militants have been blamed for thousands of deaths since launching an insurgency against the government in 2009.
Borno is one of three northeastern states where President Goodluck Jonathan declared a state of emergency and deployed additional troops in May to fight Boko Haram. Rights groups have criticized the military for heavy-handed operations they say have led to hundreds more deaths.